title: Electrophysiological properties of the superior vena cava and venoatrial junction in patients with atrial fibrillation: relevance to catheter ablation.
abstract: BACKGROUND
  Although the superior vena cava (SVC) has been well known to be one of the important foci triggering atrial fibrillation (AF), its electrophysiological characteristics have received little research attention. The aim of this study was to investigate the electrophysiological properties of the SVC and venoatrial junction (VAJ).
  
  
  METHODS
  Twenty-five consecutive AF patients without structural heart disease undergoing electrical SVC isolation were included in this study. After pulmonary vein isolation, a circular decapolar catheter and 2 multipolar catheters were emplaced in the VAJ, right atrial appendage (RAA), and SVC, respectively. Burst pacing and single extrastimulus were applied from the RAA and SVC. The atrial and caval potentials on the circular catheter in the VAJ were investigated.
  
  
  RESULTS
  Intracaval conduction delay and various degrees of conduction block over the VAJ were observed with burst pacing from both the RAA and SVC. A single extrastimulus from the RAA and SVC with a basic cycle length of 600 milliseconds prolonged the conduction time via the VAJ by 81 ± 49.7 milliseconds and 61 ± 58.7 milliseconds, respectively. The atrial and caval electrograms at the VAJ, which were separated from each other by pacing applications, facilitated mapping of the earliest activation site at the VAJ.
  
  
  CONCLUSIONS
  Intracaval conduction delay and decremental conduction property via the VAJ were demonstrated using pacing maneuvers. Pacing applications from the RAA or SVC can help distinguish the atrial and caval potentials and can facilitate mapping of the optimal ablation sites to isolate the SVC.
authors.affiliation: Department of Cardiology, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Fukumoto
authors.forename: Seiji
authors.initials: S
authors.lastname: Takatsuki
authors.forename: Takehiro
authors.initials: T
authors.lastname: Kimura
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Nishiyama
authors.forename: Kojiro
authors.initials: K
authors.lastname: Tanimoto
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Aizawa
authors.forename: Yoko
authors.initials: Y
authors.lastname: Tanimoto
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Fukuda
authors.forename: Shunichiro
authors.initials: S
authors.lastname: Miyoshi
authors.forename: Keiichi
authors.initials: K
authors.lastname: Fukuda
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000002:abnormalities / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000002:abnormalities / Q000503:physiopathology* / Q000601:surgery; D016896:Treatment Outcome; D014683:Vena Cava, Superior / Q000002:abnormalities / Q000503:physiopathology* / Q000601:surgery
keywords: atrial fibrillation; catheter ablation; decremental conduction; superior vena cava; venoatrial junction